Something like this should do it.
Code:
$rr = ObjCreate("RoadRunner.sdk")
$var = $rr.getinfo("w_tmp")
$var = StringTrimLeft($var, 3)
$var = StringStripWS($var, 8)
;MsgBox(4096, "Result", $var)
$rr.execute("SETVAR;MYTEMP; &$var")
Then you should have MYTEMP showing only 75 instead of 75*F